1. Field
The exemplary embodiments generally relate to substrate processing apparatus, and more particularly, to handling of the substrates.
2. Brief Description of Related Developments
Handling substrates with one or more of a high degree of bow, warp and size variation poses a challenge to robotic substrate handling apparatus. Generally each of these three substrate conditions requires dedicated end effector geometry such that, for example, (1) an end effector for handling one size substrate may not be suitable for substrates of other sizes, and (2) an end effector for handling a non-bowed or non-warped may not be suitable for handling bowed or warped substrates.
Locations and positions of substrates within a substrate holding station also must be detected so that substrates may be transferred to and from the substrate holding station with the robotic substrate handling apparatus. Generally, a mapping device mounted on an end effector, such as on tines of the end effector, is used to map the locations and orientations of the substrates in the substrate holding station where, for example, the end effector moves a substrate scanning sensor past the substrates in the substrate holding station. In another instance, a stationary sensor may be used to scan the substrates in the substrate holding station for determining the substrate locations and orientations. However, an ideal location of the substrate scanning sensors, when mounted to the tines of the end effector, may not facilitate an ideal position of the tines for handling the substrates.
In addition, the mapping devices mounted to the end effector for mapping the substrates are generally required to be in close proximity to the substrates being mapped. The close proximity of the mapping devices to the substrates may be problematic when bowed and/or warped substrates are scanned or when multiple sized/shaped substrates are to be supported by the same end effector.
It would be advantageous to have an end effector solution that is configurable and re-configurable to handle multiple sized substrates, bowed substrates and/or warped substrates. It would also be advantageous to provide an end effector solution that is configurable and re-configurable to provide both ideal substrate mapping sensor positions and ideal substrate handling tine positions for the same or different sized substrates, bowed substrates and/or warped substrates.